Scene swapping with delay

Getting Started
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1

I’m trying to create a script that will, after a delay, swap the scene. Right now, the player character will move into the end point which will run a script that activates an animation with a level complete screen, and I’m trying to make it so that a few seconds after this run (so that the player can look at it for a second) the next scene will start. The script for the scene swap is in a completely different script from the one used to start the animation, so I have no clue how to call for it to be used in the Game Manager. Additionally, I’m also unsure of how to properly delay the script.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.SceneManagement;

public class GameManager : MonoBehaviour
{

    bool gameHasEnded = false;

    public float restartDelay = 1f;

    public GameObject completeLevelUI;


    // Start is called before the first frame update
    public void EndGame ()
    {
        if (gameHasEnded == false)
        {
            gameHasEnded = true;
            Debug.Log("GAME OVER");
            Invoke("Restart", restartDelay);
        }

       
    }

    void Restart()
    {
        SceneManager.LoadScene(SceneManager.GetActiveScene().name);
    }



    public void CompleteLevel()
    {
        completeLevelUI.SetActive(true);
    }

}
//This is the Game Mananger

//This is the next scene script

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.SceneManagement;

public class NextLevel : MonoBehaviour
{
    // Start is called before the first frame update
    public void LoadNextLevel()
    {
        SceneManager.LoadScene(SceneManager.GetActiveScene().buildIndex + 1);
    }
}